Sheet-metal expansible elbow



D. A. RITCHIE.

SHEET METAL EXFANSIBLE ELBOW.

APPLICATION men mm; 28. 1955.

L1 9 5. Patented Aug. 1, 1916.

rm: "can: rnsxs 0a.. mmwumm, waxnm: mu. 0. c,

TTE TT DAVID A. RITCHIE, OF CAMBRIDGE,,MASSACHUSETTS.

SHEET-METAL EXPA NSIBLE ELBOW.

Application filed June 28, 1915.

To all whom it may concern:

lie it known that I, DAVID A. RITCHIE, a citizen of the United States, residing in Cambridge, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Sheet-Metal Expansible Elbows, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawings representing like parts.

This invention relates to an expansible sheet metal elbow of the character shown and described in U. S. Patent N. 34-2465 granted to me May 25, 1886, wherein sheet metal blanks having "longitudinally extended corrugations are fastened together by locked seams, on the top and bottom surfaces of the pipe elbow. The members or parts of the pipe elbow shown in the patent referred to have heretofore been made from curved sheet metal blanks of approximately the same curvature as the curve of the finished elbow. The curved blanks are cut out of flat sheets and corrugated longitudinally, and owing to the curved shape of the blanks, a very considerable surface area of the flat metal sheet is wasted, which increases the cost of the corrugated pipe elbow. Another objection is that the corrugated members when locked together have the seams on the top and bottom, or what may be considered the outer and inner surfaces, namely, those of greatest and smallest curvatures, with the result that when placed in operative position, one of the seams appears on the outside of the pipe elbow and presents a more or less unfinished and objectionable appearance.

The present invention has for its object to provide a sheet metal pipe elbow having longitudinal corrugations, which is less expensive to make, as it can be formed from substantially rectangular blanks with the least possible amount of waste metal, and which presents smooth, neat and finished seamless outer and inner surfaces. To this end, each member of the corrugated sheet metal pipe elbow is made from a substantially rectangular and preferably oblong metal blank, which by suitable dies is provided with the desired curvatures and with corrugations and side flanges extended lengthwise of the blank, the side flanges on the opposite sides of the curved blank being of equal length and extended laterally with relation to the longitudinal center of Specification of Letters Patent.

Patented Aug. i, rare.

Serial No. 36,857.

sheet metal pipe elbow is produced, which is I provided with longitudinally extended corrugations, which are free from seams on the outer and inner surfaces, and consequently when the corrugated elbow is placed in operative position and is connected with a corrugated straight piece or length of pipe, a more finished and neater piping job is obtained, for the unseamed corrugated surface of the elbow registers with the unseamed corrugated surface of the straight p1ece of corrugated sheet metal pipe. Each member of the corrugated elbow forms onehalf of the same, and the seams formed by the interlocked side flanges appear at the sides of the elbow and are substantially diametrically opposite.

The particular features of the invention will be pointed out in the claim at the end of this specification.

Figure l is a side elevation of a corrugated sheet metal pipe elbow embodying this invention. Fig. 2, a cross section of the pipe elbow shown in Fig. 1. Fig. 3, represents a flat metal sheet sub-divided into rectangular blanks from which the members of the elbow shown in Fig. l are formed; Fig. 4:, a developed view of the corrugated outer or upper member of the elbow shown in Fig. 1, and Fig. 5, a developed view of the corrugated inner or lower member.

Referring to the drawings, (4 represents the outer or upper member and Z) the inner or lower member of a corrugated pipe elbow embodying this invention. The members ct, Z), are made from flat sheet metal blanks 0, (Z, which may be of the same length or as ispreferred, the blank (Z, may be made slightly shorter than the blank 0, which are rectangular in shape, as represented in Fig. 3. By reference to Fig. 3, it will be seen that the blanks 0, (Z, may be cut from a flat metal sheet without waste. The blanks 0, (Z, are then placed between suitable dies and are bent to impart to them the proper or desired curvature both longitudinally and transversely to form one-half of the pipe elbow, and at the same time are provided with longitudinallv extended corrugations 10 and with side flanges 12, which latter are extended laterally with relation to the longitudinal curve of the members. The side flanges 12 of the member a are of the same length, and the side flanges 12 of the member I) are of the same length (see Figs. 4 and 5). The member a is applied to the member I) with the side flanges 12 in contact, and the latter are then interlocked by suitable machinery, not shown, so as to secure the two members together to form the pipe elbow shown in Fig. 1.

By reference to Figs. 1 and 2, it will be seen that each transversely curved and ngitudinally corrugated member a, 6, forms substantially one-half of the pipe elbow, and that the seams 15 are located midway between the outer and inner curved surfaces and at the sides of the elbow; consequently the outer and inner longitudinally rugated elbow so as to leave the outer and inner longitudinally corrugated surfaces of said elbow smooth and seamless.

In testimony whereof, I have signed my name to this specification 1n the presence of: two subscribing witnesses.

DAVID A. RITCHIE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

